\$Id: daml-ont.daml,v 1.2 2000/11/14 06:16:00 connolly Exp \$ The most general class in DAML. the class with no things in it. for disjointWith(X, Y) read: X and Y have no members in common. for type(L, Disjoint) read: the classes in L are pairwise disjoint. i.e. if type(L, Disjoint), and C1 in L and C2 in L, then disjointWith(C1, C2). for unionOf(X, Y) read: X is the union of the classes in the list Y; i.e. if something is in any of the classes in Y, it's in X, and vice versa. cf OIL OR for disjointUnionOf(X, Y) read: X is the disjoint union of the classes in the list Y: (a) for any c1 and c2 in Y, disjointWith(c1, c2), and (b) i.e. if something is in any of the classes in Y, it's in X, and vice versa. cf OIL disjoint-covered for intersectionOf(X, Y) read: X is the intersection of the classes in the list Y; i.e. if something is in all the classes in Y, then it's in X, and vice versa. cf OIL AND for complementOf(X, Y) read: X is the complement of Y; if something is in Y, then it's not in X, and vice versa. cf OIL NOT for oneOf(C, L) read everything in C is one of the things in L; This lets us define classes by enumerating the members. for item(L, I) read: I is an item in L; either first(L, I) or item(R, I) where rest(L, R). for cardinality(P, N) read: P has cardinality N; i.e. everything x in the domain of P has N things y such that P(x, y). for maxCardinality(P, N) read: P has maximum cardinality N; i.e. everything x in the domain of P has at most N things y such that P(x, y). for minCardinality(P, N) read: P has minimum cardinality N; i.e. everything x in the domain of P has at least N things y such that P(x, y). for inverseOf(R, S) read: R is the inverse of S; i.e. if R(x, y) then S(y, x) and vice versa. compare with maxCardinality=1; e.g. integer successor: if P is a UniqueProperty, then if P(x, y) and P(x, z) then y=z. aka functional. if P is an UnambiguousProperty, then if P(x, y) and P(z, y) then x=z. aka injective. e.g. if nameOfMonth(m, "Feb") and nameOfMonth(n, "Feb") then m and n are the same month. for restrictedBy(C, R), read: C is restricted by R; i.e. the restriction R applies to c; if onProperty(R, P) and toValue(R, V) then for every i in C, we have P(i, V). if onProperty(R, P) and toClass(R, C2) then for every i in C and for all j, if P(i, j) then type(j, C2). for onProperty(R, P), read: R is a restriction/qualification on P. for toValue(R, V), read: R is a restriction to V. for toClass(R, C), read: R is a restriction to C. for qualifiedBy(C, Q), read: C is qualified by Q; i.e. the qualification Q applies to C; if onProperty(Q, P) and hasValue(Q, C2) then for every i in C, there is some V so that type(V, C2) and P(i, V). for hasValue(Q, C), read: Q is a hasValue qualification to C. An Ontology is a document that describes a vocabulary of terms for communication between (human and) automated agents. generally, a string giving information about this version; e.g. RCS/CVS keywords for imports(X, Y) read: X imports Y; i.e. X asserts the* contents of Y by reference; i.e. if imports(X, Y) and you believe X and Y says something, then you should believe it. Note: "the contents" is, in the general case, an il-formed definite description. Different interactions with a resource may expose contents that vary with time, data format, preferred language, requestor credentials, etc. So for "the contents", read "any contents". for equivalentTo(X, Y), read X is an equivalent term to Y. default(X, Y) suggests that Y be considered a/the default value for the X property. This can be considered documentation (ala label, comment) but we don't specify any logical impact.